CD Projekt RED - Interview @ DSO Gaming

DSOGaming: The Witcher 3: Wild Hunt is powered by REDengine 3. What are the key differences between REDengine 2 and 3?

BT: The key difference is that REDengine 3 is made to support open world games. We spent a lot of time figuring out the pipeline and the systems and techniques needed to enable our game teams to achieve their goals, both in terms of storytelling and openness. We also rewrote the renderer to support DirectX 11 – this brought a lot of new features that we can use to make our games look even better.

DSOGaming: What are the key tech features of The Witcher 3, and what is the one that you are really proud of?

BT: We are very proud that The Witcher 2 is considered one of the best looking games on the Xbox 360, so we’ve tried to improve our graphics and we are very satisfied with our initial results. Naturally, we are proud that we made the transition to run our games on multiple platforms and to create the systems for an open world. We also switched our physics middleware from Havok to PhysX and we started using Apex. These were all really big changes and we are far from done – we have a lot more on our plate, including constant improvements to our editor. We should probably get back to this question after the game is released but right now these things come to mind first.

DSOGaming – Readers’ Question – How has native 64-bit affected the engine? How did you achieve a world 35 times larger than Skyrim The Witcher 2 and what does it imply about the engine, performance, and requirements? Can you share any estimated minimum/recommended PC requirements?

GR: Well, 64-bit architecture gave us access to larger amounts of memory available for the game. I think that’s the biggest benefit. In general the transition to 64-bit went quite smoothly and seamlessly for us.

I admit that the size of the world we have in TW3 provided us with a considerable number of technical challenges. It pushed us to rewrite our streaming system, memory management and resource handling mechanisms. It also required a lot of enhancements from us to the tools used by designers and artists. Many things that were done manually in TW2 had to be automated now to allow us to fill the vast areas Geralt will travel through faster.

It will obviously cause TW3 to have higher requirements than previous installments of the game. But at this stage, without final optimizations, it’s hard to estimate what the minimum system requirements for comfortable playing will be. We will definitely work hard to make this game playable on most gaming PCs.

It's difficult to do anything with any physics right now that's of any consequence because the consoles just don't have the power to do it. As long as games have to be ported to the old consoles, physics will be stuck with flapping flags and blowing newspapers around.

(City of Heroes was actually doing pretty good physics several years ago back when PhysX was its own company. No worries about the consoles when you're doing an MMO!)

It's not confusing, it's exactly the same as the previous gen of consoles running PhysX in software. You can run Havok in software too, so doesn't explain why you'd want to switch from Havok or a non-propriatory physics middleware to PhysX without an incentive from nVidia.

Originally Posted by GothicGothicness
Well, for sure phys x is going to be able to run with directcompute or similiar on the AMD GPU.

Nope. If you have an AMD GPU then physX will only run in software on the CPU, and poorly at that.

Even UE4 has built in phys X, none would choose this if it didn't run in hardware on next-gen consoles.

It runs in software on next-gen consoles, but presumably in not as crippled a form as for PCs.

Phys X has no license cost, compared to exspensive havok, unless you want to have a source code license, but probably even that will save compared to havok.

Or bullet, or other openCL or directCompute based physics or.. there are plenty of other options. None of which will come with the nVidia engineer time that PhysX does, but the cost is paid by the PC gaming market in that case.